Innovations in battery technology and microelectronics are now finding wide acceptance in the design of new prosthetic and orthotic appliances, while the actuators used to produce motion and force in these devices remain essentially unimproved. The overall goal of this multi-phase, expanded SBIR project is to adapt a new class of "active" materials--developed to efficiently convert electrical energy directly into motion and force for aircraft and spacecraft applications--into a technically advanced "bioactuator." Specifically designed for high-performance prosthetic devices such as hands, wrists, elbows, and shoulders, these novel bioactuators will also allow clinicians to create a new generation of "intelligent," "power-assisted" orthotic braces and supports that are not currently feasible. In Phase I, active material actuator capsules will be designed and integrated into additional hardware needed to drive practical appliances. Extensive functionality and reliability testing will be conducted on a prototype device to validate its performance and to make a determination of overall feasibility for continued development in Phases II and II. Successful completion of these multiple phases of work is expected to yield a family of bioactuators-each providing different output characteristics required for various appliances, but all tailored to provide the natural appearance and wide-ranging functionality that users desire in synthetic hand and limb replacements. These robust new bioactuators are anticipated to replace the fragile micrometer and gear-based devices that represent the current state of the art by offering much greater reliability, smaller size, lower weight, and lower overall cost to users. Their substantially improved performance and flexibility will allow clinicians to create prosthetic and orthotic appliances offering the comfort, natural appearance, and functionality long sought by users. In addition, the compact nature of active materials will be fully exploited to create small appliances ideally suited to children's functional needs.